Rolling contact fatigue of case carburized steels

The model was used to compare the rolling contact fatigue (RCF) lives of through hardened and case carburized bearing steel with different case depths at contact pressures ranging from 2 to 3.5 GPa. The effect of residual stress distribution on RCF lives was also investigated. The results show that there is an optimum case depth for which maximum RCF lives can be attained. The spall shapes and the depth below the surface where damage initiates were found to be dependent on the case depth. The model was also used to study the effect of initial material imperfections. The fatigue lives and their dispersion quantified by Weibull slopes obtained from the model correlate well with the experiments.